Method of making a carrying case



July 26, 1966 E. VIDAL 3,263,009

METHOD OF MAKING A CARRYING CASE Original Filed Nov. 28, 1961 2 Sheets-Sheet 1 FIG.

INVENTOR EUGENE L. VIDAL AT RNEVS .IuIy 26, 1966 E. VIDAL 3,253,009

METHOD OF MAKING A CARRYING CASE Original Filed Nov. 28, 1961 2 Sheets-Sheet 2 MOLTEN PLASTIC BLOW MOLDING REMOVING END CUTTER I! ILA L/ l LIFIIFIIIIIHIP INVENTOR J EUGENE I .VIDAI REMOVING BOTTOM BLANKS BY Fla. 2 r X w United States Patent 3,263 009 METHOD OF MAKING A CARRYING CASE Eugene L. Vidal, Avon, Conn., assignor to Phillips Petroleurn Company, a corporation of Delaware Original application Nov. 28, 1961, Ser. No. 155,312, now

Patent No. 3,151,762, dated Oct. 6, 1964. Divided and this application May 8, 1964, Ser. No. 371,866

4 Claims. (Cl. 26498) This is a continuation-in-part of the copending application of Eugene L. Vidal, Serial No. 862,651, filed December 2 9, 1959, and now abandoned.

This is a division of parent application, Serial No. 155,312, filed November 28, 1961, now Patent No. 3,151,762.

This invention relates to a method of making a onepiece carrying case of monocoque or hollow shell construction having an open interior free of compartmentforming partitions.

The carrying cases used today in handling bottles are heavy cases, usually made of wood, sometimes of metal, which are partitioned to separate the bottles. Although cardboard cartons have been found suitable for packaging canned goods and disposable bottles, such as liquor bottles, they are not sufficiently durable for repeated use in handling reuseable bottles, for example, soft drink and beer bottles on which deposits are paid by the consumer. The carrying cases for these reuseable bottles must be suificiently durable and weatherproof to withstand the usual handling and treatment to which such carrying cases are subjected by the bottling works ma chinery, in transporting the filled bottles, stacking and storing the carrying cases, both filled and unfilled, and returning the empty bottles.

More recently, lighter plastic carrying cases have been introduced, but they have not proved satisfactory because they lack the necessary lighter weight rigidity and their high material cost prevents them from competing economically with the conventional wooden cases.

The thin-wall monocoque or shell-like construction of the present invention provide-s a durable carrying case which is light in Weight, competitive in price and far more attractive than conventional carrying cases. Also, it is lighter, more rigid and less expensive than recently proposed plastic designs. The one-piece, thin skin monocoque construction imparts considerable rigidity to the case and the open interior free of compartment-forming partitions decreases the weight and expense of the case and at the same time facilitates cleaning the interior of the case. Within the hollow interior of the carrying case, an array of upstanding tapered positioners formed integrally with the bottom define article-receiving areas which keep the lower ends of the articles separate; in addition, these tapered positioners serve as guides to insure that the bases of the articles are directed to the article-receiving areas and also that the article stands upright in the case when it is dropped into the case on the oblique or bounced in the case due to rough handling. The top of the carrying case is a cover-like separator having openings therein in alignment with the article-receiving areas below to keep the upper ends of the articles separate and in upright condition within the carrying case. These openings are preferably internally curved or flanged to stiffen the top of the case and guide and position the articles dropped into the openings.

Ancillary features of the carrying case of the present invention, in its preferred form, include registering formations on the case to facilitate stacking when the case is empty, registering formations on the case to facilitate stacking when the case is filled, comfortable gripping slots at both ends of the case, and the upstanding, hollow,

cross-shaped guides in the bottom of the case which not only define the article-receiving areas, but also prevent the upper ends of the bottles or other articles in the lower case of a stack from entering the openings exposed in the bottom and thereby make the stacking of filled cases more exacting.

The unique carrying case of the present invention is made by blow-molding extruded synthetic plastic material to form a hollow, closed shell of substantially uniform wall thickness and then removing the blank or blanks from the shell to define the necessary opening or openings therein. The hollow molded form preferably incorporates laterally extending closed formations at each end which are easily out 01f to provide gripping slots for the carrying case. The blow-molding method of making the carrying case permits the use of molds of up to onetenth the cost of molds required for injection molding, and even more important, it makes possible the overall thin wall construction which contributes to the low cost of the carrying case. Incidentally, the molding of the upstanding tapered guides from sheet material without leaving exposed openings in the bottom of the carrying case large enough to receive the upper ends of bottles in a lower case of a stack presented something of a challenge in a blow-molding operation and was solved by the unique configuration of the upstanding guides. The configuration of these guides, therefore, is directly related to the blow-molding operation.

For a more complete understanding of the present invention, reference can be made to the detailed description which follows and to the accompanying drawings in which:

FIGURE 1 is a sectional view of a carrying case decribed and claimed in Serial No. 155,312, filed November 28, 1961, now Patent No. 3,151,762, the carrying case being shown at an intermediate stage of its manufacture after the molding operation.

FIGURE 2 is a schematic drawing of the method of manufacture of the carrying cases in accordance with the present invention.

The carrying case of the present invention is made by blow-molding a hollow, closed shell 10' shown in FIG- URE 1 of the drawings. In this process a pair of extruded sheets or a parison or tube of the plastic material is introduced between two inexpensive matrix mold sections, and when the mold sections are brought together air or other gaseous fluid is introduced into the tube or between the sheets to bring them into pressure engagement with the contour of the closed mold. Following the molding operation, the molded form is cooled and the mold is opened to permit removal of the hollow, closed shell 10". Blanks 18' (see FIGURE 1) are then cut out of the top 14 to make the openings 18, which are defined by internally extending flanges which stiffen the shell, blanks 20 are removed from the bottom 11 to make the openings 20, and the closures 19' which extend laterally from both end walls are cut off to define the open gripping slots 19. This extremely simple process is readily adapted to mass production techniques which, of course, is essential to the low cost of the product.

The closed shell 10' can be made so that the top is characterized by one large rectangular blank surrounded by a downwardly extending lip or flange spaced near the sides of the shell. When this large blank is removed, an open-top carrying case remains. In addition, the top of the closed shell can be made with four such rectangular blanks, and upon removal thereof four six-pack cartons can be carried in the case. The inside upper edgestiffening lip or flange, impractical to form in molding processes other than blow-molding, permits the ends and the sides of the case to have outside flush surfaces which are required if the cases are to be handled by conventional conveyor belts used in the bottling works.

FIGURE 2 more particularly points out the process of making carrying cases in accordance with the practice of this invention. Referring to the figure, molten plastic is fed to an extrusion die and a pair of extruded sheets or a parison or tube of the plastic material is extruded therefrom. The extruded material is introduced between two matrix mold sections of the desired configuration. As illustrated, each mold section contains shallow projections, i.e., projections which extend only a relatively short distance toward the opposite wall. The space left around each projection on one wall provide an area in which are formed the edge-stiffening flanges which surround the openings 18. The projections on the other wall form the upstanding tapered guides 16 when the article is blown. The matrix mold sections are movable in the direction indicated by the arrows. When the mold sections are brought together, air or other gaseous fluid is introduced into the tube or parison or between the sheets to bring them into pressure engagement with the contour of the closed mold. Following the molding operation, the molded form is cooled and the mold is opened to permit removal of the hollow closed shell formed therein. The closures which extend laterally from both end walls are then cut oif to define the gripping spots in the bottle carrier. Subsequently, top and bottom blanks are removed from the hollow closed shell. Although various cutting methods can be employed, one method of cutting which is particularly applicable is by utilizing saws or saw-type blades. If this method is utilized, considerable advantage will be realized in the elimination of stress on the mold materials. Also, in cutting the top and bottom openings, various combinations of directions of rotation of the several circular saws shown can be used to counter balance the torque exerted by an individual saw and thereby eliminate unduly stressing the hollow molded article.

The invention has been shown in its preferred form and by way of example only, and various modifications and variations may be made therein without departing from the spirit of the invention. The invention, therefore, is not to be limited to any particular form or embodiment, except insofar as such limitations are expressly set forth in the claims.

I claim:

1. A process for making a one-piece carrying case comprising the steps of:

(a) in a multi-piece mold, one piece of which is provided with at least one projection which extends only a relatively short distance toward an opposite wall, said projection being so shaped and spaced as to provide in said mold a space along said projection in which an upper edge-stiffening flange portion will be formed,

(b) blow molding a plastic material in said mold in a manner so that there will be formed in said mold a substantially closed, hollow rectangular shell having an upper edge-stiffening flange formed in said space, thus also forming a recessed portion in the surface of said shell, said flange and said recessed portion substantially encompassing said projection;

(c) cutting said recessed portion along a line substantially at the base of said stiffening flange, thus forming an open top, one-piece carrying case having a reinforcing edge-stilfening flange at the open top thereof;

((1) removing said recessed portion; and

(e) forming in at least one wall of said shell a hand grippable holder whereby the case thus formed can be carried.

2. A process for making a carrying case for bottles and the like which comprises:

(a) in a two-piece mold, one piece of which is provided with a plurality of cruciform projections and the other piece of which is provided with a plurality of shallow circular projections, said projections being so shaped and spaced as to provide in said mold spaces along said projections in which upper edgestiffening flanges will be formed, blow molding a hollow closed shell having a bottom, sides and a top, the said top having a plurality of circular depressions and edge-stiffening flanges formed by the said circular projections and said spaces, said flanges and said depressions substantially encompassing said projections, the bottom having a plurality of cruciform depressions formed by the said cruciform projections,

(b) removing said hollow shell from said mold,

(c) forming bottle receiving apertures in the top of said shell by cutting out and removing the bottom portion of each of said circular depressions, and

(d) removing portions of the end walls of said shell whereby hand holes for carrying said carrying case are formed.

3. The process for making a one-piece carrying case for bottles and the like comprising the steps of:

(a) forming a pair of extruded sheets;

(b) introducing said extruded sheets between two mold sections, one of which sections is provided with at least one shallow projection, said projection being so shaped and spaced as to provide in said mold a space along said projection in which an upper edge-stiffening flange portion will be formed;

(0) closing said mold sections above said extruded sheets;

(d) introducing gaseous fluid under pressure between said extruded sheets to bring them into pressure engagement with the contour of said closed mold sections, whereby a hollow molded form having laterally extending, closed, cross-sectionally elongated, symmetrically disposed projections at each end and the top having a recessed wall surrounded by an internally extending flange is formed, said recessed wall being formed by said shallow projection, said flange and said recessed wall substantially encompassing said projection;

(e) cooling the resultant mold form;

(f) separating the mold sections whereby the said molded form can be removed;

(g) cutting said recessed wall in a plane parallel and substantially adjacent to said flange, and removing a blank from the top of said form whereby an opening into which at least one bottle can be introduced is formed in the upper surface of said mold form;

(h) removing a plurality of blanks from the bottom of said mold form to provide openings for elimination of dirt and liquid; and

(i) cutting off said laterally extending projections to provide gripping slots for the carrying case.

4. The process for making a one-piece carrying case for bottles and the like comprising the steps of:

(a) extruding a parison of thermoplastic material,

(b) introducing said parison between two mold sections, one of which sections is provided with at least one shallow projection,

(c) closing said mold sections about said parison,

(d) introducing gaseous fluid, under pressure inside said parison to bring the same into pressure engagement with the contour of said closed mold sections, whereby a hollow molded form having laterally extending, closed, cross-sectionally elongated, symmetrically disposed projections at each end and the top having a recessed wall surrounded by an internally extending flange is formed, said recessed wall being formed by said shallow projection, said flange and said recessed wall substantially encompassing said projection,

(e) cooling the resultant mold form,

(f) separating the mold sections whereby the said molded form can be removed,

(g) cutting said recessed Wall in a plane parallel and substantially adjacent to said flange, and removing a blank from the top of said form whereby an opening into which at least one bottle can be introduced is formed in the upper surface of said mold form,

(h) removing a plurality of blanks from the bottom of said mold form to provide openings for elimination of dirt and liquid; and

(1') cutting off said laterally extending projections to provide gripping slots for the carrying case.

References Cited by the Examiner UNITED STATES PATENTS ROBERT F. WHITE, Primary Examiner.

1O ALEXANDER H. BRODMERKEL, Examiner.

M. H. ROSEN, A. R. NOE, Assistant Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,263,009 July 26, 1966 Eugene L. Vidal It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4 line 61 after "projection" insert said projection being so shaped and spaced as to provide in said mold a space along said projection in which an upper edgestiffening flange portion will be formed Signed and sealed this 1st day of August 1967.

(SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, Jr. 

1. A PROCESS FOR MAKING A ONE-PIECE CARRYING CASE COMPRISING THE STEPS OF: (A) IN A MULTI-PIECE MOLD, ONE PIECE OF WHICH IS PROVIDED WITH AT LEAST ONE PROJECTION WHICH EXTENDS ONLY A RELATIVELY SHORT DISTANCE TOWARD AN OPPOSITE WALL, SAID PROJECTION BEING SO SHAPED AND SPACED AS TO PROVIDE IN SAID MOLD A SPACE ALONG SAID PROJECTION IN WHICH AN UPPER EDGE-STIFFENING FLANGE PORTION WILL BE FORMED, (B) BLOW MOLDING A PLASTIC MATERIAL IN SAID MOLD IN A MANNER SO THAT THERE WILL BE FORMED IN SAID MOLD A SUBSTANTIALLY CLOSED, HOLLOW RECTANGULAR SHELL HAVING AN UPPER EDGE-STIFFENING FLANGE FORMED IN SAID SPACE, THUS ALSO FORMING A RECESSED PORTION IN THE SURFACE OF SAID SHELL, SAID FLANGE AND SAID RECESSED PORTION SUBSTANTIALLY ENCOMPASSING SAID PROJECTION, (C) CUTTING SAID RECESSED PORTION ALONG A LINE SUBSTANTIALLY AT THE BASE OF SAID STIFFENING FLANGE, THUS FORMING AN OPEN TOP, ONE-PIECE CARRYING CASE HAVING A REINFORCING EDGE-STIFFENING FLANGE AT THE OPEN TOP THEREOF, (D) REMOVING SAID RECESSED PORTION; AND (E) FORMING IN AT LEAST ONE WALL OF SAID SHELL A HAND GRIPPABLE HOLDER WHEREBY THE CASE THUS FORMED CAN BE CARRIED. 